The present invention relates to an imaging device provided in a mobile information terminal, etc.
In recent years, the mobile information terminal into which a small size camera is installed is observed with interest. The image that is picked up by the user can be transmitted to a third person by a mobile information terminal with a camera.
FIG. 25 is a block diagram showing a configuration of the normal imaging device employed in the mobile information terminal. In FIG. 25, the image that is picked up by an imaging portion 111 is signal-processed by a signal processing portion 3 and is displayed on a displaying portion 4. Operations of the imaging portion 111, the signal processing portion 3, and the displaying portion 4 are controlled by an imaging controlling portion 6, a signal process controlling portion 7, and a display controlling portion 8 in a controlling portion 5. More particularly, the imaging controlling portion 6 controls the exposure correction and the white balance correction of the imaging portion 111, the signal process controlling portion 7 controls the image processing such as the expansion/contraction of the image, and the display controlling portion 8 executes display/non-display of the picked-up image, the display position control, etc. In this manner, the good picked-up image can be obtained by executing the automatic exposure and the auto white balance control.
In the imaging device provided to the mobile information terminal, etc., the case where the scene that is in front of the cameraman (opposing image) is picked up and the case where the cameraman himself (own image) is picked up can be considered. Since the opposing image and the own image have different objects and are exactly opposite in the imaging direction, different imaging controls must be applied to the opposing image and the own image to get the good image.
For example, as shown in FIG. 26, if it is tried to pick up the opposing image under the circumstance where the opposing image is positioned in the front-light state and then pick up the own image under the same circumstance, the image of the cameraman is picked up in the backlight state and thus the good own image cannot be picked up. Also, in many liquid crystal panels used as the display member of the mobile information terminal, in order to improve the outdoor visibility, normally the reflecting plate for reflecting the incident light (in this case, the solar light) is provided as the underlying layer of the liquid crystal panel and then the liquid crystal panel surface is irradiated from the back by the light reflected by the reflecting plate. As a result, as shown in FIG. 26, if the image is picked up in the situation that the light is irradiated onto the display screen, the own image is picked up in the backlight state.
The present invention is made to overcome the above subject, and it is an object of the present invention to provide an imaging device which is capable of obtaining good opposite and own images in the mobile information terminal having an imaging function, etc. without the influence of imaging circumstances.
An imaging device according to the present invention comprises a member for picking up a first image and a second image; a member for calculating a feature quantity of a luminance in a central portion and a peripheral portion of the first image, and adjusting the luminance in the first image such that an addition value of a value that is obtained by multiplying the feature quantity of the luminance in the central portion of the first image by a first coefficient and the feature quantity of the luminance in the peripheral portion of the first image becomes a first target value; and a member for calculating the feature quantity of the luminance in the central portion and the peripheral portion of the second image, and adjusting the luminance in the second image such that an addition value of a value that is obtained by multiplying the feature quantity of the luminance in the central portion of the second image by a second coefficient, which is set independently of the first coefficient, and the feature quantity of the luminance in the peripheral portion of the second image becomes a second target value.
The second coefficient is set larger than the first coefficient.
Also, the second target value is set larger than the first target value.
Also, an area of the central portion of the first image is set larger than an area of the central portion of the second image.
Also, weighting rates of luminance component integrated values in respective central portions of the first image and the second image are set to about 4:7.
Also, an area of the central portion in the second image is set to about xc2xc of an overall area of the second image.
Also, an imaging device further comprises a member for converting a tone of the luminance in the second image.
Also, an imaging state of the second image is detected, and the tone assigned to a low luminance component that is lower than a predetermined value is increased if the second image is positioned in a backlight state.
Also, an imaging device further comprises a member for synthesizing the first image and the second image.
Also, the first image and the second image are picked up by an imaging member that is rotatably supported to a main body.
Also, an imaging device further comprises a first lens member for forming an image corresponding to the first image; a second lens member for forming an image corresponding to the second image; and a member for selecting one of images formed by the first lens member and the second lens member, and forming a selected image onto an imaging surface of an imaging member.